Fumeproof spray cabinet



March 3, 1931.

A. C. GOETHEL FUMEPROOF SPRAY CABINET Filed June 28, 1926 2 Sheets-Sheetl w a ZN VEN TOR.

ATTORNEYS March 3, 1931.

A. C. GOETHEL FUMEPROOF SPRAY CABINET 1926 2 Sheets-Sheet. 2 7

Filed June 28 INVENTOR. WC. eilvb h w+ &

ATTORNEY.

Patented Mar. 3, 1931 rman eon r inr or MILWAUKEE, W sconsin EUMELERQQEsPnaY CABINET I Application filed June '28,

This invention relates; to improvements infume proof 'spraycabinets. 1

Such cabinets are usually providedwlth powerful airdraftSWhich not onlyinterfere saidslotted tubes, showing a portion of the 55 with theapplication of the spray the operator, but also-subjec th per tor toconsiderableinconvenience, annoyance, and, attimes, to danger fromchilling drafts. It has also been foundthat, the use of-powerful Waircurrents carry away large quantities of the material duringpainting,- varnishing, or

other-spraying operations, and arefrequently ineffective to fullyaccomplish the object of protecting the workmen from. the fumes andrebounding atoms of poisonous ordeleterious substances. 7 I, i I f a kThe object of this invention isto provide a cabinet having an open side1 protected by an effective air curtain between the 'position'occupiedby the operator and theobject to be sprayed. Y V

A further object is to provide means, wherebysuch an air curtain can beproduced by air currents having minimum volume and pressure or velocity,whereby materials, heavier than the air may be permitted to pass bygravity to thebottomof'thecabinet, and whereby"workmen' may be protectedwith minimum inconvenience andmaximum secu- -rity.v I V A further objectof the invention to provide means; whereby air under '--press'ureslightly greaterthan that in the atmosphere, may be delivered in itheformof converging sheets "across ac'abinet opening and withdrawn bysuction induced by an ejector" air current in an exhaust passage,therebyi-avoid- 1 ing the use ofsucti on fans for exhaustingair "fromthe cabinet and avoiding theuse of any "other movable. parts in" theexhaust passage which might become c' logged by= materials condensed orprecipitated from the'ioutgoing air. t l V "In the drawings i "sage.

views.

r-sn ze a cras seem; V ew 'e s'io 192 s r lito, 119,041.

the slotted tubes employed for producing the air curtaimthe sectionbeing taken on line 2-2 of Figurel," p ,I

F'gure 3 's a fragmentary view; ofone of provedcabinet. 1

i ures is a sectional view. of- ,portions of the baffle curtains,'drawnon linef5 -{i fof 9.

Figure 4;; t

Like parts are identified by the same ref- 7 eren'ce charactersthroughoutv the several The improved cabinet has" a as wall 10 which isprovided with apertures near the front corners throughwhich air supplypipes 11; extend, these, pipes being elbowed above the top wall andconnected with an air supply main 12 leading from any suitable source,such as a fanvor pump. Thefronto fthe cabinet is open exceptalong'themargins and side walls, which are preferablyprovided withinturnedflanges .13,i-which may compriseportions of corner pieces, or anglepieces, secured to the margins of these walls. Ineachfront cornerof'the-s'pace enclosed vby the walls of the cabinet, a substantiallyyertiQaIly dispQsed, slotted'tube 15 iscon-i ,n e'teagtaone or thepipes'll andhas' avclosed 2 lcw erclld which is preferably tapered as.in-

iafi a 1 Swed n a Q p-s p do'r Liter -re e m 7. s c dt h be Wall'lS orbeam19; of the cabinet. Each tube 15 is not only provided with a.longitudinal 8 slot 20, but the sidemargins of this" slot are fla ked bys li wa d y. P ojec i fl ges 21 whi h orm hat may b te m d-a .n z e slotthrough; which a sheet of airmay flow, the I dimensions of which fromtop to bottom are substantially equal to the vertical ,di-

Zmension' of the opening at the front of the V Y'cabinetL- The' slottedtube 15 has its upper 1 v 1 t g endrotata'blyseated over the loweren'dof the; v {Figurel is av'ertica-l"sectional view of the" improvedcabinet, drawn'to'a central Plane, ichn lude fli esi le the a stresupplypipe or duct ll'so that'by' rotating the mb rs; the air may bedirected .throughfthe slet: atflthe 'desiredlpitch or: angle of diverfIgencefrom'the planejof the opening i'n the 7 front of'theeab'inetf iI"- pipe 27 leading from the main '12 downward-* ly through an aperturein said top wall, with another elbow 28 within the cabinet, as clearly'shown in Figure l.

At the rear, the cabinet is provided with rearwardly converging backwalls'30 leading to an outlet aperture 31 with which a stack. or outletflue 32 is connected.v An induced.

draft is preferably promoted in this outlet flue by means of a pipe 33leading from the main 12 into the flue "andprovided with an upturnedelbowed portion 34:. The lower.

portion of the flue is large enough to allow for the space occupied bythe ejector pipe 33 sothat thispipeoffers no material obstruction to theflow of air outwardly through the flue. Battle curtains are preferablysuspended in the rear portion of the cabinet to prevent particles of thesprayed material from being carried'by the air into'the outlet flue toany great extent. These baffles are preferably formed of thin sheetmetal chan- 'nel bars 35, those in the rear curtain being staggered withreferenceto those in the front curtain, whereby the air strikes thebaflles and is deflected in order to pass between those of the frontcurtain and those of the rear curtain, as indicated by the arrows inFigure '5.

These baffles are preferably suspended from Y the upper portion of theback wall by means of suitable brackets 37. Theside walls of the cabinetmay be provided with openings which are normally closed by slides ordoors rized as follows: The object to be painted,

In order to control the quantity of air to bedelivered to the respectiveslotted tubes j Q and and through the: ejector tube 33, "each of thetubes 11,27 and-33 isprovided witha gate valve 40 which may be opened orclosed to a desired extent to regulate theproportionatequantityof air tobe delivered through the tube. i

fume proof cabinet may be briefly summavarnished, or otherwise sprayed,'will' be placed within the cabinet in front of the baffles 35', and theslotted'no z'z'le tubes jwill be adjusted fordelivery'of three sheets ofair-across the cabinet in frontjof'the object,

two of these sheets; coming from the tubes 15 at the respective sidesnear the front corners and-the third sheet coming from'the top. Thetubeswillpreferably be adjusted in such a manner that the sheets of air willconverge toward a point lorsareain front of the object. The upperportions of theair sheets of airconverge.

currents from the tubes 15 will of course intersect portions of thesheet of air delivered from the upper tube 25, but this intersectionwill occur near the side walls of the cabinet and the resultingdeflections will be clownwardly and toward the center, therebyincreasing the thickness of the air current in frontof the'obj ect to besprayed. Theentire body of air will of course move rearwardly along.oblique lines and will eventually pass the'object in thedi're'ction ofthe outlet 31, the capacity of which is such as to provide for awithdrawal of all of the air which passes through the tubes; 15 and 25,together with some additional air entering the cabinet through the openfront.' I have discovered that these obliquely moving sheets of air forma curtain which effectively intercepts and deflects all reboundingparticles and reversely moving fume carrying currents,

whereas air currents moving directly from frontto rear frequentlydevelop counteractlng currentsbycontact with the rear walls andbafliesand'these tend to carry the fumes and entrained particles of poisonousmaterial outwardly through the front of the cabinet. 1 I have alsodiscovered thatthese low velocity oblique currents, delivered in thevform of sheets of converging air int-he direction .of an outlet throughwhich air is being exhausted under light suction, not only deflectrebounding particles and eddies, but that they also tend toprogressively neu tralize each other as to initial direction and combineto. form, a continuously; flowing steady through the exhaust, flue. 1

current of air passing outwardly lI claim 1 I 1. The combination ofaspray cabinet pro vvldedywlth an opening. flanked by: slotted tubesatthe sides and top thereof, means for dellvering air underpressur'e tosaidslotted tubes, means foradjusting said tubes to. direct the airthrough, saidslots in inwardly converging sheets, and means forwithdraw-' ingairjfrom the 'side ofthe cabinet: toward which said sheetsof air'fconverge.

2The combination. ofa spraycabinet pro- .vided with an openingfianked'byslotted. V tubes'atthe sides andtopthereof, means The mode, ofoperationof the improved for deliveringair under pressure to said slotted tubes,means for adjusting saidtubes tubes; and -means 1 for withdrawing airfrom the side of the cabinet toward which. said 3. The combinationofasprayfcabi'net provided' with-an opening; in v its front wall Vflanked by axially; adjustable slotted tubes, air directing q flangesextending outwardly from said tubes along the side margins of theslotstherein, and means for supplying air under pressure to: said tubesin independently V controlled volume, each of said tubes being rotatablyadjustable to regulatethe pitch of the air current delivered through itsslot, I said cabinet having an outlet n he side opposite said tubes.

4. The combination of a spray cabinet pro-.

vided with amain for supplying air under pressure, of a set of branchpipes leading f from said main downwardly andthrough the Walls of thecabinet near the front upper corners thereof, vertically extendingslotted 7 tubes rotatably embracing the delivery ends.

of some of said pipes, and a horizontally extending slotted tuberotatably embracing the delivery end of another of said pipes, said lastmentioned pipe having a horizontally disposed extremity, said cabinethaving an opening in its front Wall flanked by said tubes at the sidesand top and said tubes being rotatably adjustable to directv sheets ofair convergingly toward the central portion of the cabinet.

5. In a spray cabinet having an open front Y and an outlet, thecombination With air delivery tubes upon opposite sides ofsaid openfront adapted to deliver air across said opening, of an ejector inoperative relation to said outlet, an air supply main connected Witheach of said tubes and With said ejector, and means for controlling theflow of air from said supply main to each of said tubes and said ejectorindependently to substantially balance the volume of air; dischargedinto and Withdrawn from the cabinet,

6. In a spray cabinet having an open front and an outlet, thecombination of means for passing air through said cabinet in substantialabsence of in-draft through said open front, said means comprisingperforated conduit means adapted to discharge sheet-like streams of airacross said open front, air supply means for said conduit means, saidairsupply means having an intake remote from said open front, and meansfordrawing the air through said outletat substantially the rate ofdischarge inthe cabinet' and discharging it at a point remote from bothsaid intake and said open front.

ALFRED o. GOEVIIHEL.

